Fluid-compressor.



S. H. HUMAN. FLUID COMPRESSOR. APPLICATION FILED OCT. I5, 1915 1 ,Q'YKQQQ. Patented Sept. 3, 1918.

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FLUID COMPRESSOR. APPLICATION FILED OCT. I5. I915.

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SUEL E. HUMAN, OF CHICAGO, ILLINOIS.

FLUID-COMPRESSOR Specification of Letters Patent.

Patented depth. 3, 1119118.

Application flled October 15, 1915. Serial m. 55,969.

To all whom it may. concern:

Be it known that I, SAMUEL H. HUMAN, a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented a certain new and useful Improvement in Fluid-Compressors,

of which the following is a full, clear, concise, and exact description, reference being had to the accompanying drawings, forming a part of this specification.

This invention relates to air compressors, or pumps, and more particularly to the mechanism for operating the piston whereby a structure simple and inexpensive to manufacture and one having few parts capable of getting out of order is obtained.

The principal feature of my invention resides in the cam, or eccentric, structure by means of which the piston is reciprocated without theuse of the usual connecting or piston rod, and without the accompanying pivot or bearing. The principal advantage in addition to simplicity lies in the method y which the parts of my pump are maintained lubricated. I

In order to properly lubricate a pump provided with the usual connecting, or piston, rod it is necessary that the pump be driven at a speed suflicient to cause a s lash of the oil'against the sides of the cylin er and onto the shaft by which the piston rod is connected with the piston. By my present invention, however, oil is carried up to the piston by means of a rotated ring, or cam, and is deposited upon the piston base plate upon which it travels through capillary attraction to the walls of the cylinderthus lubricating all of "the movable parts of the pump without the necessity of the usually required splash and without the necessity of auxiliary oiling devices such asoil cups, wicks, and

the like.

Other features of my invention are the details of construction by means of which spring pressure is applied to the piston to drive it 1n a non-compress ng d rection without at the same time introducing unnecessar air space between the pistonand the cylinder head such as would result from the placing of an ordinary spring above the piston and within the cylinder.

My invention is illustrated in the m anyi'ng drawin' s in whlchsimilarparts are characters, and m which,

esignated by preferably made of cast iron. The base 10 is provided 'with a cylindrical threaded secured, this ball-race being'mounted upon Figure 1 is an elevation showing the slidmg gear by means of which the pump shaft may be moved into and out of registration with a source of power.

Fig.2 is a section through the pump taken on the line 22 of Fig. 5.

Fig. 3 is a partial horizontal section taken upon the line 3-3 of Fig. 2.

Fig. 4 is a vertical section taken line 4 -'4 of Fig. 1.

Fig. 5 is an end elevation of the device.

Fig. 6 is a modification of the piston operating cam, or eccentric.

Fig. 7 is a section taken on the line 77 of Fig. 6; and

Fig. 8 is still another modification of the on the piston operating cam, or eccentric.

The opposing portions of my pump comprise a base 10, preferably made of cast aluminum, and a top, or cylinder portion 11,

opening into .which an externally threaded portion of the cylinder portion 11 screws, this portion being providedwith a shoulder 12 which abuts the horizontal top face of the base portion 10. Journaled in bronze bearings 14, one at each end of the base portion 10, is a shaft 15 whichcarries a gear 16 fitted to the shaft by means of a key 21, this gear being arranged to be moved longitudinally upon the shaft by meansof a lever 25 supported by a bracket 17 which is preferably clamped upon the bearing housing 18 at oneend of the base portion 10. In order that the lever and gear will remain in the position in which they have been set provide a spring pressed plunger 19 WlllCh is so carried upon the lever that 1t 1s pressed in one or the other of the notches 20 1n the lever bracket, depending upon the position of the lever.

Upon that portion of the shaft 15 WhlCh lies within the base portion 10 and-between the end bearings 14 a circular ball-race 22 1s the shaft in an eccentric position so that as the shaft rotates the ball-race will be caused to oscillate a distance of substantially onehalf an inch. Spacedfrom the ball-race 22 .is an internally grooved rin 23', the groove thereinprovidin a secon ball-race for the balls-24, a su cient depression being cut in each of the members 22 and 23 for the insertion of a ball at one position so that the members 22 and 23 may be assembled in close rolling contact with the balls Whic separate them.

The piston 26 is provided with the usual rings 2 and oil spaces 28 and is of sufiicient height to be maintained in proper alinement within. the cylinder despite a slight shifting of the point of application of the power from the center line thereof. This piston, which is preferably made of cast metal, is internally threaded at its lower and open end and into this threaded open.- ing is screwed a plate 30, this plate being provided with a pair of diametrically opposite openings 31 into which a spanner may be placed in order to properly tighten the plate 30 into position. The opposite walls of the piston are slotted to receive the bar 32 which by its extensions through diametrically opposite slots 33 in the outer wall of the cylinder prevents the piston from rotating in the cylinder. The bases of these slots form abutments for the "rod 32 to limit the downward movement of the piston thus aiding in the assembling operation. The opposite ends of the bar 32 are provided, as shown in Figs. 2 and 3, .with square members 34 which have upwardly and downwardly extending cylindrical portions 35 and 36, the portion 35 extending into openings in the protruding ends of the bar 32 and themembers 36 extending upwardly to maintain the alinement of the springs 37 which act to press the bar 32, and hence the piston, in a downward direction. The spring housing 38, which is a portion of the cylinder casting, is prefer- .ably closed by a plate 39 which may bear. the manufacturers name, or other insignia. This plate has an opening therein near the upper end through which air may be drawn into and expelled from'the space below the piston during the operation of the device. Intake and exhaust valve mechanism 40 and 41' is mounted on the top of the cylinder casting, this mechanism being of any desired or well-known form and constituting no'part of my present invention, it being preferable, however, that the valve mechanism be brought substantially flush with the top of the cylinder so that upon the com- "pletion of the power stroke of the piston into substantial contact with the cylinder head substantially all of the air will be ejected from the cylinder.

In Figs. 6 and 7 I have illustrated a modification of the ball bearing type of eccentric in WlllCh the portion 43 carried by the rotating shaft is in direct contact with the [ring 44, the ring being maintained in proper position thereon by means of screws 45,]the heads of which overlap the inner circumference of the ring. In Fig. 8 I have illustrated still a further navvaao this modification is somewhat greater than it is in the use of the other modifications the fact that the surface of the cam 47, shown in Fig. 8, dips into the oil during each revolution provides a film of oil between the cam and the base of the piston which prevents excessive wear during the operation of the device especially if the parts are constructed of hardened steel.

My pump is preferably so proportioned that the rod 32 abuts the base 42 of the slot 29 before the cam has reached the lowest position of its eccentric movement so that throughout a small fraction of the rotation of the cam the ring 23, or 44, as the case may be, will be free from contact against the base plate 30 of the piston. This will permit the ring '23 or 44 to rotate with the inner eccentric portion throughout a small fraction of the rotation of the shaft, thereby carrying a quantity of oil up to be deposited upon the base of the cylinder plate 30 when the ring again comes in contact with that plate. This is not essential in case the pump is to be driven at high speeds, but is very desirable for low speed operation since it is only by this method that the oil is efiectively carried onto the cylinder base.

In the operation of the device the shaft 15 may be rotated at any desired speed and ineither direction. As the body of the cam moves upward the ring 23 comes in contact with the base plate 30 and immediately assumes a rolling engagement therewith, the rotation of the ring 23 ceasing immediately upon its contact with the plate 30. As the cam 22 proceeds to rise the ring 23 presses the piston up in the cylinder and thus ejects the air through the exhaust valve which had previously been sucked in above the piston through the intake valve. When the camhas passed what may be termed its dead center and has started upon "its downward stroke the springs 37 force is particularly useful for attachment to automobile engines for'compressing air for tires, and air starters, though I do not wish to be in any manner limited to this use of the invention, it being applicable to any other use in which air or fluid is required to be pumped. Although my improvemnt is described with respect to the details of construction herein illustrated it is to be understood that many modifications may be made without departing from the spirit or scope of my invention.

What I claim is:

1. An air compressor comprising, a reciprocating piston and cylinder therefor, springs for pressing the piston in the noncompression direction, a straight continuous operating shaft, an eccentric carried thereon, a ring rotatable on the eccentric and having rolling engagement'with the piston whereby in the rotation of the shaft the piston is moved in the compression direction, said ring being arranged to rotate at intervals out of engagement with said piston, whereby new operating surfaces of said ring will engage the piston.

2. A compressor comprising, a piston and cylinder therefor, a base portion having-an oil reservoir therein, a horizontal shaft having bearings in said base portion above the level of the oil in the reservoir, an eccentric carried upon said shaft, a ring rotatable upon said eccentric and adapted in its eccentric movement by said shaft to dip into the oil in the oil reservoir, said ring serving as the operating means for said piston and having a rolling and non-frictional contact with the base of said piston, the movement of said eccentric being such as to carry the ring out of engagement with the base of said piston during a portion of the rotation of the shaft whereby the ring has a rotary movement in the oil and thereby carries oil onto the base of the piston whereby the oil is distributed to the cylinder walls and to the shaft bearings.

3. A compressor comprising, a piston and cylinder therefor, a straight continuous-operating shaft extending horizontally below the base of the piston, an eccentric ball race carried by the shaft and rotatable therewith, a ring surrounding the eccentric ball race and having an internal ball race therein, balls between the eccentric ball race and the ring providing a ball bearing for the rotation of the ring about the eccentric ball race, said ring being adapted to be brought into engagement with the base of the piston to move the piston in the direction for compression, and means for returning the piston in the direction opposite to compression in contact with said ring, said ring having a rolling and non-frictional contact with the base of said piston but adapted to be separated therefrom at intervals during which the ring rotates freely so as to present a new contact surface to the piston.

4. In a compressor the combination with a cylinder of, apiston therein, a rod extending across the piston and through slots in the walls of the cylinder, spring means engaging said rod outside the cylinder to press it and the piston in' the direction opposite to the compression stroke, and means engaging the piston at substantially its central portion for moving it in the direction for compres- SlOIl.

5. In a. compressor the combination with a cylinder of, a piston therein, a rod extend ing across the piston and through slots in the walls of the cylinder, spring means engaging said rod outside the cylinder to press it and the piston in the direction opposite to the compression stroke, and a cam engaging the piston at substantially its central portion for moving it in the direction for compression.

6. In a compressor the combination with a cylinder of, a piston therein, a rod extending across the piston and through slots 1n the walls of the cylinder, spring means enaging said rod outside the cylinder to press it and the piston in the direction opposite to the compression stroke, a shaft extending parallel to the base of the piston, a cam carried upon said shaft, and adapted in the rotation thereof to press. the piston in the direction of compression.

7 In a compressor the combination with a cylinder of, a piston therein, a rod extending across the piston and through slots in the walls of the cylinder, spring means engaging said rod outside the cylinder to press it and the piston in the direction opposite to the compression stroke, a base portion having an oil reservoir therein, and a cam adapted to rotate within the base portion and to dip beneath the oil in said oil reservoir, said cam serving in its rotation to lift the piston in the direction of compression.

8.In a compressor the combination with a cylinder having diametrically opposite slots through its walls, a piston for the cylinder, a bar extending through the slots in the cylinder walls and engaging the piston and adapted to reciprocate with the piston, said bar having depressions in the projecting ends thereof, a pair of members each having a protuberance extending into the depressions in said bar, said members engaging the outer wall of the cylinder to maintain the bar in position, and spring means engaging said members to press them, and hence the bar and piston in the direction opposite to compression, and positive means for pressing the piston in the direction of compression,

9. A compressor comprising a piston and cylinder therefor, an oil reservoir, a horizontal operating shaft, an eccentric carried upon said shaft, a, ring rotatable upon said eccentric and adapted in its eccentric movement by said shaft to dip into the oil in the oil reservoir, said ring serving asthe operat ing means for said piston and having a rolling and non-frictional contact with the base of said piston, the movement of said eccen-' trio being such as to carry the ring out of engagement with the base of said piston durin a portion of the rotation of the shaft, where y the ring has a rotary movement in the oil and thereby carries oil onto the base of the piston.

10. In an air com ressor the combination with a base member having an oil reservoir therein, a shaft extending horizontally across the oil reservoir, a cam carried by said shaft and comprising an inner member rigidly secured to the shaft and having a V shaped groove in its periphery, a ring about said inner member and having an internal V shaped groove therein and balls between. the inner and outer V shaped grooves, a piston adapted to be engaged by said ring, and means whereby said ring presents different faces for contact with said piston whereby the wear thereon is equally SAMUEL H. HUMAN.

WVitnesses: A. G. lvIOCALnB, H. A. NEIBURGER. 

